Boss is having another agenda
Assume that your boss has a different (hidden) agenda, when he redirects conversation back to him, revisiting subjects repeatedly. Manipulating you, he swings from highly emotional about a point to nonchalant. Be aware of his body language, listen to what is not being sad. Compare his actual behavior with his usual ways of behaving (too bad if there is no difference). Check the facts, ask open questions starting by what, why, how. Switch on your "bullshit meter".